In this study, chitosan/sodium alginate/nano cellulose (CSA-N) nanocomposite hydrogels were prepared using a completely green route and used as sorbents to adsorb Cd2+ ions from water and soil systems of an environmental aspect. The sorbents were characterized by FTIR, SEM, and XRD. The influences of initial Cd2+ concentration, the presence of nano cellulose, type of the polluted environment, and ionic strength on adsorption and desorption isotherms were investigated. The maximum adsorption capacity of cadmium onto CSA was significantly increased from 2264.9 to 4380.97 μmol/g when the system was changed from soil to water, respectively. While, the maximum adsorption capacity of cadmium onto CSA-N was almost the same in the soil and wastewater systems, i.e., 3419.5 and 3230.3 µmol/g, respectively. The results indicated that Langmuir and Freundlich models provided the best fit for the experimental adsorption data for CSA and CSA-N, respectively. By comparing the amounts of Δq, the difference between adsorption and desorption amounts, the CSA was not economically feasible sorbent at high initial concentrations of Cd2+ in the wastewater system, while, CSA-N was demonstrated to be a more efficient adsorbent than CSA for cadmium removal from both the soil and wastewater systems.